3c) Explain three reasons why biodiversity in tropical rainforest should be preserved

Explain: Give a detailed account giving reasons or causes.
1) Maintain the food chain – a linear sequence of links in a food web starting from a species that eats no other species in the web and ends at a species that is eaten by no other species in the web. Plants are the primary producers. Insects and animals are consumers that rely on plants to provide them for food. As humans are on the top of the food chain, we rely on the primary producers and consumers etc. to supply us with food. Without biodiversity, humans would lose their food source and eventually die off.

2) Biodiversity sustains our lives and the earth. Plants, animals and micro-organisms supply humans with a multitude of free ecological services, such as generating soil, controlling pests, balancing atmospheric gasses and many other biological processes. These processes are vital to our existence, and for the health of the planet. For this reason it is essential for our well-being that we protect biodiversity - the variations in species, their lives and their habitats - because biodiversity is necessary for sustaining life and our standard of living.

3) Humans rely on plants for many types of medicines. Medicines for heart disease, for example, are still produced today from wild foxgloves. Wild plants are constantly being screened in search of cures for cancer, AIDS and other diseases. We can never tell which species might prove useful: chemicals extracted from jellyfish, for example, are now being used by medical researchers studying the development of cancers.

Links:
http://www.capenature.co.za/biodiversity.htm?sm%5Bp1%5D%5Bcategory%5D=595